A heater control system including a control unit enclosing a housing having a thermocouple operated unit therein is known. An opening in the housing leading to a thermocouple operated unit, and a thermocouple having an end or tip which is secured into the opening for operational connection to the thermocouple operated unit are also known. Positioning the end of the thermocouple in a certain axial position in the opening relative to the housing, in which the housing includes a securing device, the end of the thermocouple has a securing device cooperating with the housing securing device to secure the end and the housing together in a desired axial position, and the thermocouple securing device includes an externally threaded nut-like fitting threaded into a threaded section of the housing opening are all known. For example, see Katchka et al U.S. Pat. No. 4,285,662 and Caparone et al U.S. Pat. No. 3,508,708.